[MaupitiBlue]

I think amyjess is right.

From the Restatement Second:

§ 90. Promise Reasonably Inducing Action or Forbearance

(1) A promise which the promisor should reasonably expect to induce action or forbearance on the part of the promisee or a third person and which does induce such action or forbearance is binding if injustice can be avoided only by enforcement of the promise. The remedy granted for breach may be limited as justice requires.

If Oracle says "go ahead and use it" and then sues you for having used it, they lose. If they sue you to stop using it going forward, they win.

[torstenvl]

I can understand how you'd think that, reading the text of the rule in the Restatement. However, at common law - and as shown in the examples if you'd keep reading - there has to be some detrimental reliance. Being able to use a product isn't in an of itself to your detriment. However, hiring someone based on that understanding might be.

A, knowing that B is going to college, promises B that A will give him $ 5,000 on completion of his course. B goes to college, and borrows and [[[spends more than $ 5,000 for college expenses.]]] When he has nearly completed his course, A notifies him of an intention to revoke the promise. A's promise is binding and B is entitled to payment on completion of the course without regard to whether his performance was “bargained for” under § 71.

(detrimental reliance in triple square brackets)

I have a hard time imagining a case being granted summary judgment for the defendant just because Oracle's customer sales rep told him "we don't really care."

In all honesty, the legal issue is more likely to be whether the person on the phone had apparent authority to grant a license. Even if a promissory estoppel theory would work, the person speaking to you would still have to be in some position (or appear to be in some position) to bind Oracle to a promise he/she made.